A bottom anti-reflective coating comprising an organic polymer layer having substantially no nitrogen and a low compressive stress in relation to a polysilicon layer is employed as the lower layer of a bi-layer antireflective coating/hardmask structure to reduce deformation of a pattern to be formed in a patternable layer. The organic polymer layer is substantially transparent to visible radiation, enabling better detection of alignment marks during a semiconductor device fabrication process and improving overlay accuracy. The organic polymer layer provides excellent step coverage and may be advantageously used in the fabrication of structures such as FinFETs.
Legal claims defining the scope of protection, as filed with the USPTO.
1. A structure formed during manufacture of a semiconductor device, the structure comprising: a patternable layer formed above a substrate; an antireflective coating comprising an organic polymer layer of poly-p-xylylene formed over the patternable layer, and a silicon oxynitride layer formed over the organic polymer layer; and a photoresist pattern formed over the silicon oxynitride layer.
2. The structure recited in claim 1 , wherein the organic polymer layer absorbs radiation in the ultra-violet and deep ultra-violet range.
3. The structure recited in claim 1 wherein the organic polymer layer is substantially transparent to visible radiation.
4. The structure recited in claim 1 , wherein the organic polymer layer has substantially no nitrogen.
5. The structure recited in claim 1 , wherein the organic polymer layer comprises a gas phase depositable organic polymer.
6. The structure recited in claim 1 , wherein the patternable layer is a polysilicon layer.
7. The structure recited in claim 6 , wherein the organic polymer layer has a lower coefficient of thermal expansion differential with respect to the patternable layer than amorphous carbon layer.
8. The structure recited in claim 1 , wherein the organic polymer layer is formed by a Chemical Vapor Deposition (CVD) process.
9. The structure recited in claim 1 , further comprising an oxide layer formed between the substrate and the patternable layer.
10. A method of fabricating a semiconductor device having a multi-layered anti-reflective coating, the method comprising: forming a patternable layer above a substrate; forming an organic polymer layer of the anti-reflective coating over the patternable layer, wherein the organic polymer is poly-p-xylylene; forming a silicon oxynitride layer of the anti-reflective coating over the organic polymer layer; and forming a photoresist pattern over the silicon oxynitride layer.
11. The method recited in claim 10 , wherein the organic polymer layer absorbs radiation in the ultra-violet and deep ultra-violet range.
12. The method recited in claim 10 , wherein the organic polymer layer is substantially transparent to visible radiation.
13. The method recited in claim 10 , wherein the organic polymer layer has substantially no nitrogen.
14. The method recited in claim 10 , wherein the organic polymer layer comprises a gas phase depositable organic polymer.
15. The method recited in claim 10 , wherein the patternable layer is a polysilicon layer.
16. The method recited in claim 15 , wherein the organic polymer layer has a lower coefficient of thermal expansion differential with respect to the patternable layer than amorphous carbon layer.
17. The method recited in claim 10 , wherein the organic polymer layer is formed by a Chemical Vapor Deposition (CVD) process.
18. The method recited in claim 10 , wherein forming a patternable layer above a substrate further comprises forming the patternable layer on an oxide layer formed on the substrate.
Cooperative Patent Classification codes for this invention. Click any code to explore related patents in that topic.
December 31, 2002
March 8, 2005
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